1. Field of the Invention
The present invention relates to camera exposure meters and in particular to such exposure meters usable in both a reflected light mode and an incident light mode.
2. Description of the Prior Art
Prior art exposure meters usable in both a reflected light mode and an incident light mode are basically of the incident light type. Such exposure meters are provided with a conversion table determined by assuming an average reflectance of an ordinary object for use in the reflected light mode. When the exposure meter is used in the incident light mode, an incident light mode attachment is mounted on the exposure meter and a correct exposure value is obtained by direct display readouts from the exposure meter. When use in the reflected light mode, the attachment is exchanged for a reflected light mode attachment and a correct exposure value is obtained by converting the displayed value according to the conversion table. Accordingly, when used in the reflected light mode, prior art exposure meters of this type pose a drawback, wherein the correct exposure value is unobtainable unless the conversion table is used in the reflected light mode, thereby taking much time to obtain an exposure value, and furthermore, a wrong value may be used as a correct exposure value when the conversion table is not used or is misinterpreted.
Moreover, with another type of prior art exposure meter, a rotatable plate, on which a plurality of display values corresponding to the values measured by the exposure meter are printed, is rotatably provided. The angle of rotation of the plate is determined by the exposure information to be displayed. Over the rotatable plate is a display plate with a display window therein for readout of values on the rotatable plate. A user of the exposure meter manually switches the position of the display window according to the use of the exposure meter in a reflected light mode or an incident light mode. This type of exposure meter, however, like the aforementioned prior art device, poses a drawback in that a wrong value may be obtained for a correct exposure value when the position of the display window is not switched.